Aims: To evaluate the influence of different polymerization protocols on the shear bond strength (SBS) of various composite materials used for orthodontic attachment fabrication, and to analyze the potential interaction between material type and light-curing time. Materials and Methods: Four composite materials for attachment fabrication were tested: Omnichroma and Omnichroma Flow Bulk (Tokuyama Dental), GC Ortho Connect Flow (GC Orthodontics), and G-aenial Universal Injectable (GC Corporation). All materials were applied using an etch-and-rinse technique with orthophosphoric acid for 30 seconds with Scotchbond Universal adhesive, except for GC Ortho Connect Flow, which was used following phosphoric acid etching only. In vitro samples were prepared from healthy molars, divided into 8 groups based on material and polymerization protocol, and composite resin cylinders (n= 15 each group) were reproduced using a Teflon ring mold (1.84 x 3 mm). A VALO Cordless LED lamp was used for curing: -20 seconds traditional polymerization (670 mW; 900 mW/cm²) -3 seconds – Extra Power mode (1570 mW; 2100 mW/cm²) After storage at 37 °C and 100% relative humidity for 24 hours, micro-shear bond strength test (μSBS) was performed using UltraTester (Ultradent Products. South Jordan, UT, USA). Statistical analysis was conducted using two-way ANOVA (α = 0.05), following verification of normality (Shapiro–Wilk test) and homogeneity of variances (Brown–Forsythe test). Results: A statistically significant main effect was found for material type (p < 0.001) and polymerization time (p = 0.002), with a significant interaction between the two factors (p = 0.027). Increasing curing time to 20 seconds significantly improved SBS values only for Omnichroma and GC Injection. Omnichroma Flow Bulk exhibited the highest SBS values under the 3-second curing protocol, performing significantly better than the other materials under this condition. Conclusions: Material type represents the primary determinant of orthodontic attachment bond strength. The effectiveness of the polymerization protocol is material-dependent: certain composites maintain high bond strength even with reduced curing times, potentially allowing shorter clinical procedures without compromising adhesive reliability.
Florenzano, F., Incerti Parenti, S., Chiara D'Alessandro, A., Alessandri Bonetti, G. (2026). Optimization of bonding of Orthodontic Attachment: Role of Polymerization Protocol and type of Composite Material.
Optimization of bonding of Orthodontic Attachment: Role of Polymerization Protocol and type of Composite Material
Federica Florenzano;serena incerti parenti;Giulio Alessandri BonettiUltimo
2026
Abstract
Aims: To evaluate the influence of different polymerization protocols on the shear bond strength (SBS) of various composite materials used for orthodontic attachment fabrication, and to analyze the potential interaction between material type and light-curing time. Materials and Methods: Four composite materials for attachment fabrication were tested: Omnichroma and Omnichroma Flow Bulk (Tokuyama Dental), GC Ortho Connect Flow (GC Orthodontics), and G-aenial Universal Injectable (GC Corporation). All materials were applied using an etch-and-rinse technique with orthophosphoric acid for 30 seconds with Scotchbond Universal adhesive, except for GC Ortho Connect Flow, which was used following phosphoric acid etching only. In vitro samples were prepared from healthy molars, divided into 8 groups based on material and polymerization protocol, and composite resin cylinders (n= 15 each group) were reproduced using a Teflon ring mold (1.84 x 3 mm). A VALO Cordless LED lamp was used for curing: -20 seconds traditional polymerization (670 mW; 900 mW/cm²) -3 seconds – Extra Power mode (1570 mW; 2100 mW/cm²) After storage at 37 °C and 100% relative humidity for 24 hours, micro-shear bond strength test (μSBS) was performed using UltraTester (Ultradent Products. South Jordan, UT, USA). Statistical analysis was conducted using two-way ANOVA (α = 0.05), following verification of normality (Shapiro–Wilk test) and homogeneity of variances (Brown–Forsythe test). Results: A statistically significant main effect was found for material type (p < 0.001) and polymerization time (p = 0.002), with a significant interaction between the two factors (p = 0.027). Increasing curing time to 20 seconds significantly improved SBS values only for Omnichroma and GC Injection. Omnichroma Flow Bulk exhibited the highest SBS values under the 3-second curing protocol, performing significantly better than the other materials under this condition. Conclusions: Material type represents the primary determinant of orthodontic attachment bond strength. The effectiveness of the polymerization protocol is material-dependent: certain composites maintain high bond strength even with reduced curing times, potentially allowing shorter clinical procedures without compromising adhesive reliability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
